Why you and your dog should steer clear of blue-green algae

It doesn’t take much to get a water-loving dog to jump in. This dog is perfectly safe fetching his ball, but pet owners should be careful to check out the water conditions before a dog gets near the water.
(Photo: Stanimir G.Stoev/Shutterstock)

On a sunny June day on Prairie Lake in Minnesota, the Tatge
family was tossing tennis balls in the water for their Labrador, Copper, to
catch. But after playing for a few minutes, Copper stumbled to the shoreline
and collapsed, obviously in great agony.

The one odd thing about the water that day was the cloud of
green slime floating on the surface,
recalls Brock Tatge, Copper's owner. Copper died a few hours later at the veterinarian's office. The doctor who examined
him believed the retriever died after ingesting toxins from blue-green algae in
the water.

Blue-green algae, or cyanobacteria,
turn lakes a distinctive hue when conditions are right for the growth of algal
blooms. In addition to producing a thick mat of green scum and an offensive
smell, sometimes blue-green algae also produce
microcystins,
toxins that can be deadly to dogs, livestock and other animals within hours of
contact.

Typically, when a person looks at the soupy green swamp of a
lake overcome with blue-green algae, there's little chance he'll wade in
for a swim. But dogs are often not as discerning. They rarely have a problem
drinking or swimming in the potentially toxic green water or licking the slimy water
off their fur.

And when they ingest the microcystins, the toxins can cause a
range of symptoms ranging from mild eye irritation and diarrhea to extremely
serious health issues such as liver failure and even death,
according to the American Kennel Club (AKC).

A rise in animal illnesses

The Minnesota Pollution Control Agency started tracking dog
deaths related to suspected blue-green algae poisoning about a decade ago. After
splashing along the shore of Lake of the Woods in August 2015, a 4-year-old
springer spaniel named Layla became the 18th dog on the list, according Minnesota Public Radio News.

Jack Lundbohm, Layla's owner, told MPRN that the water turns
green on the lake nearly every summer. But he didn't start seeing the unmistakable
crud of cyanobacteria until recently.

"The blue-green algae is a totally different
beast," he said. "When it blooms, it's an awful sight. It floats in
the water like a big raft. It's almost metallic blue and green in color, and
when you drive through with your boat, it has a very strong metallic odor that
you just have to wish you'd never smelled before."

A 2013 study
uncovered 368 cases of dogs that either died or became sick from blue-green
algae in the U.S. between the late 1920s and 2012. Cases were reported
sporadically, according to the study, until the mid-'70s when cases occurred
"almost yearly."

The rise in cases could be because reporting agencies started paying more attention or it could be because instances of cyanobacteria toxicity have indeed increased. Or both.

More recently, between 2007 and 2011, 13 states reported 67
confirmed or suspected cases of dog illnesses associated with blue-green algae;
more than half of the cases were fatal.

The report detailed how the researchers believed the dogs
were exposed to the toxins:

Where blue-green algae lives

Cyanobacteria isn't limited to the occasional lake or ocean
on a hot summer day.

"You'll find it everywhere," says Ohio State
University environmental biologist Dr. Jeffrey M. Reutter, past director the
Ohio Sea Grant College Program. "It's very naturally occurring. In fact, a
good deal of the oxygen we breathe is produced by cyanobacteria in the
ocean."

Not all species are capable of producing toxins. Only about
a dozen of them cause problems when temperatures are warm — typically above 60
— and the nutrient level is high, says Reutter. And for blue-green algae, the
nutrient that matters is phosphorous. Because phosphorous levels tend to be
higher in summer, that's when the chances of coming across toxic blooms increase.

How to stay safe

One of the problems with cyanobacteria is that you can't
tell the difference between a harmless bloom and a toxic bloom just by looking
at it, says Reutter.

"Any time you see a really high concentration of the
algae, I would stay away."

That means keeping your dog (and your family) away from the
water. If your pet happens to get wet, rinse him off with clean tap water, don't let him lick his
fur, and get immediate medical attention if he starts showing any unusual
symptoms.

But animals are by no means the only ones that can get sick
from cyanobacteria.

When people come into contact with cyanobacteria through
swimming or jet skiing, symptoms can include skin and eye irritation, headaches,
fever, muscle and joint pain, blisters, diarrhea, vomiting and more,
according to the Environmental Protection Agency. Symptoms can appear within a few minutes or a few days. Really
severe cases can lead to seizures, liver failure, respiratory arrest and even
death.

"When you look at places from around the world, you
realize it's not just an Ohio, or U.S. or Canadian problem. There are places
where people have been killed from it. It's something to be taken very
seriously," says Reutter. "You
can measure toxicity a variety of ways and, in some measure, [the bacteria] are
more toxic than cyanide."